Design and Modeling of a Quadcopter with Double Axis Tilting Rotors

Multirotors are well suited for application tasks such as surveillance and exploration of otherwise inaccessible areas. Standard quadrotors have limitations in their possible configurations due to their underactuation. For this reason, some spatial configurations are not possible, such as hovering while maintaining a nonhorizontal orientation. This paper presents an overactuated quadrotor platform with double axes tilting propellers. The peculiarity of the proposed platform is that, beside the usual control on the four propellers, it allows to tilt each arm where motors are mounted along two independent axis. The resulting number of control inputs is 12, allowing a higher number of stable configurations with respect to traditional quadrotors. As a result, it can assume spatial orientations that are not possible for traditional quadcopters, enabling the possibility to deal with obstacles that would generally impede the motion of normal quadcopters. This feature allows to potentially explore a larger space....